more than one way .... ;-)
> He used a little 1" computer fan slowed down to a very slow
> speed with resistors to slowly diffuse the CO2 amongst his plants.
> It worked amazingly well and was completely safe.
>
This bit caught my eye. One word of warning for people who may be
inspired to do the same. Be careful as to the sort of fan you buy. A
lot of the modern fans are "brushless" DC motors which do not respond
to lowering the voltage (this is what the resisitors are doing -
lowering the voltage to the fan) in any useful manner. You need to
find a fan that is NOT using a brushless DC motor. Also need I say
the selection of the resistor values is empirical at best - well, not
really if you know the motor characteristics, the fan load vs rpm
(some cube law I think) the intersection of the lines should give you
the operating speed for a particular voltage.... I probably should
shutup now :-)
-- Brett Lymn, Computer Systems Administrator, AWA Defence Industries
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"Also, it takes a lot longer to get up North ..... The slow way"
- "Clever Trevor" Ian Drury